Profile editor - Clarified which LEDs are part of the selected layer

Profile editor - Re-implemented LED dimming
Profile editor - Hide layer bounds of unselected layers
Profile editor - Dim layer shapes of unselected layers (option to hide them NYI)
Profile editor - Disable edit tool when no layer is selected or the selected layer has no LEDs
Gradient picker - Fixed the preview being at a slight angle
Color brush - Fixed the gradient being at a 45 degree angle
Settings - Added color scheme option to manually switch between light and dark

src/Plugins/Artemis.Plugins.LayerBrushes.Color/ColorBrush.cs

@@ -78,7 +78,7 @@ namespace Artemis.Plugins.LayerBrushes.Color
                 GradientType.Solid => SKShader.CreateColor(_color),
                 GradientType.LinearGradient => SKShader.CreateLinearGradient(
                     new SKPoint(_shaderBounds.Left, _shaderBounds.Top),
-                    new SKPoint(_shaderBounds.Right, _shaderBounds.Bottom),
+                    new SKPoint(_shaderBounds.Right, _shaderBounds.Top),
                     GradientProperty.Value.GetColorsArray(),
                     GradientProperty.Value.GetPositionsArray(),
                     SKShaderTileMode.Repeat),